When you call the `aria.utils.Delegate.add` method, you have to also call `aria.utils.Delegate.remove` when the listener no longer needs to be called. The missing call to `aria.utils.Delegate.remove` leads to a memory leak in this case.
However, I think there is no need to add a new delegate id here, as there is already one for the whole widget. You can just catch the events you need in `_dom_onclick` and `_dom_ondblclick` (you will have to check the event target, of course, so that you only react on clicks and double clicks on the right elements as you do in `_onEditEvent`...).